Annealing of skyrmion lattice in van der Waals magnet via field modulation.

In atomic solids, annealing transforms disordered structures into ordered crystals through thermal activation, whereas realizing a comparable process in quasiparticle lattices is highly desirable. Magnetic skyrmions are topological spin textures that can form ordered lattice and undergo equilibrium phase transitions, yet thermal activation is insufficient to overcome their kinetic constraints or provide tunable control. Here, we demonstrate field-driven annealing of skyrmions in two-dimensional van der Waals Fe3GaTe2 (FGaT) at room temperature. Oscillating magnetic fields drive the formation of polycrystalline skyrmion lattices, whereas bipolar current pulses generate anisotropic hexatic states through current-induced lattice distortion. Despite distinct external fields, both processes follow similar defect-mediated crystallization dynamics. The annealing is enabled by the interplay between DMI and MA, while the thermodynamics are primarily governed by dipolar interactions. Our findings demonstrate a pathway for annealing control of topological spin textures and establish FGaT as a platform for exploring skyrmion collective behaviour and reconfigurable spintronics.